Apparatus, method for controlling apparatus, and storage medium

ABSTRACT

An apparatus includes an obtaining unit configured to obtain first image data obtained by reading, performed by a reading unit, a chart on which an image has not been formed by an image forming unit and second image data obtained by reading, performed by the reading unit, a chart formed by the image forming unit, and an estimation unit configured to change the second image data using the first image data and estimate a cause of an abnormality that has occurred in the image forming unit from a feature amount obtained by analyzing the changed image data.

BACKGROUND

1. Field

Aspects of the present invention generally relate to an apparatus and amethod for estimating, when an abnormality has occurred in a printer, acause of the abnormality, and a computer-readable storage medium forstoring a program for executing the method.

2. Description of the Related Art

In recent years, apparatuses, for example a printer, which realize imagequality of the same level as a printing machine have been introduced tothe market along with improvement in performance of electrophotographicapparatuses. It is necessary for such apparatuses to maintain high imagequality to operate similarly as the printing machine. However, if aprinter is used over a long period of time, deterioration of the printermay occur, and an abnormality with respect to the image quality mayoccur in an image output from the printer. In general, if an “abnormalimage” is generated due to such deterioration, a user who has viewed theimage and noticed the abnormality contacts a service person. The serviceperson then visits an installation location of the printer and performsmeasures. In such a case, it is difficult for the user to express inwords a state of the abnormal image caused by the deterioration and thelike. For example, if there is “unevenness”, the cause thereof cannot beidentified unless detailed information, such as a direction, frequency,and a cycle, in which the unevenness occurs is recognized. Consequently,when the user has pointed out the image abnormality, it is necessary forthe service person to visit the installation location of the printer anddirectly confirm the abnormality of the image quality. The serviceperson then predicts an abnormality location based on the confirmedabnormality and identifies service parts related thereto. The serviceperson once returns to a service base and obtains the service parts,returns to the installation location, and performs the measures. Whenthe service person performs as described above, travelling costs of theservice person becomes high. Further, since the printer cannot be useduntil the service person completes performing the measures, downtimeoccurs so that productivity of the user is greatly lowered.

To solve such an issue, Japanese Patent Application Laid-Open No.2012-22232 discusses a technique in which the image is output from theprinter to obtain a scanned image of the output image, and theabnormality is detected. Identification of the “abnormal image” is thussimplified.

However, according to the technique discussed in Japanese PatentApplication Laid-Open No. 2012-22232, if there is a cause for generatingthe abnormal image when the scanned image is obtained, an imageabnormality may be superimposed on the image abnormality which hasoriginally occurred. As a result, it may prevent detection of theoriginal image abnormality which has occurred in the printed image. Forexample, an image reading apparatus for a digital copying machine fixesthe position of an optical system and reads the image while an autodocument feeder (ADF) conveys a document (a document feeding-readingmethod).

In such a case, since the position of the reading optical system isfixed, if dust or dirt adheres at a document read position, or thedocument read position becomes scratched or smudged, the image readingapparatus continues reading, for example, the dust. As a result, alinear streak may be generated in the read image. Further, smudge of awhite plate or smudge of a mirror in a mirror unit may also beconsidered as the cause of the abnormality.

If the abnormality occurs in the reading system when the scanned imageis obtained as described above, it becomes difficult to separate thecause of the original image abnormality in the print image and the causeof the abnormal image generated when the image is scanned. Further,accuracy of detecting the original image abnormality may become lowered.

SUMMARY

Aspects of the present invention are generally directed to providing animage inspection system which correctly identifies an “abnormal image”,when the scanned image is obtained and the image abnormality hasoccurred in superimposed manner on the abnormal image generated in theprint image.

According to an aspect of the present invention, an apparatus includesan obtaining unit configured to obtain first image data obtained byreading, performed by a reading unit, a chart on which an image has notbeen formed by an image forming unit and second image data obtained byreading, performed by the reading unit, a chart formed by the imageforming unit, and an estimation unit configured to change the secondimage data using the first image data and estimate a cause of anabnormality that has occurred in the image forming unit from a featureamount obtained by analyzing the changed second image data.

According to the present disclosure, if an image abnormality hasoccurred when a scanned image is obtained, a cause of the imageabnormality in a print image which occurs when an image is output and acause of an abnormal image which occurs when an image is scanned can beeasily separated.

Further, an effect of the image abnormality in the scanned image on theprocess for detecting the image abnormality in the print image isreduced, so that the image abnormality in the print image can becorrectly detected. As a result, the cost of the service person andlowering of the user productivity after the abnormal image has occurredcan be reduced.

Further features of the present disclosure will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a system configuration example.

FIG. 2 is a diagram illustrating an example of an external view of animage forming apparatus.

FIG. 3 is a diagram illustrating an example of a structure when ascanner unit performs a document feeding-reading operation.

FIG. 4 is a diagram illustrating an example of accumulation of dust on adocument positioning glass plate.

FIG. 5 a diagram illustrating an example of a read image when dustadheres to the document positioning glass plate.

FIG. 6 is a block diagram illustrating a configuration example of acontroller.

FIG. 7 is a diagram illustrating concrete examples of image problemswhich occur in the image forming apparatus.

FIG. 8 is a block diagram illustrating a configuration example of animage inspection apparatus.

FIG. 9 is a block diagram illustrating an example of an image inspectionprogram in the image inspection apparatus.

FIG. 10 is a diagram illustrating concrete examples of analysis charts.

FIG. 11 is a flowchart illustrating an example of a process performed byan image forming apparatus according to a first exemplary embodiment.

FIG. 12 is a flowchart illustrating an example of a process performed bythe image inspection apparatus.

FIG. 13 is a flowchart illustrating an example of a chart analysisprocess performed by the image inspection apparatus.

FIG. 14 is a flowchart illustrating an example of a chart correction andanalysis process performed by the image inspection apparatus.

FIG. 15 is a flowchart illustrating an example of a process performed byan image forming apparatus according to a second exemplary embodiment.

DESCRIPTION OF THE EMBODIMENTS

Various exemplary embodiments will be described in detail below withreference to the drawings.

<System Configuration>

FIG. 1 is a diagram illustrating a configuration of a network system inwhich information on an abnormal image of each image forming apparatusis mainly communicated according to a first exemplary embodiment. Thesystem includes image forming apparatuses 101, 102, and 103, and animage inspection apparatus 110. The image forming apparatuses 101, 102,and 103 and the image inspection apparatus 110 are connected by a localarea network (LAN) 10 and capable of communicating with each other.

According to the present exemplary embodiment, information on anabnormal image which has been generated in the image forming apparatuses101, 102, and 103 is transmitted to the image inspection apparatus 110via the network. The image inspection apparatus 110 then performsanalysis and identifies a cause of the abnormal image.

<External View of Image Forming Apparatus>

FIG. 2 is a diagram illustrating an example of an external view of theimage forming apparatus according to the first exemplary embodiment.

A scanner 140, which is an image reading unit, inputs reflected lightobtained by exposure scanning performed on an image of a document usinglight emitted from an illumination lamp to a linear image sensor (acharge-coupled device (CCD) sensor). The scanner 140 thus convertsinformation on the image to an electric signal. Further, the scanner 140converts the electric signal to a luminance signal for red (R), green(G), and blue (B) colors, and outputs the luminance signal to acontroller 200 illustrated in FIG. 6 to be described below as imagedata.

The document is set on a tray 142 of a document feeder 141. When theuser gives an instruction through an operation unit 160 to start readingthe document, the controller 200 transmits the instruction to read thedocument to the scanner 140. The scanner 140 which has received theinstruction feeds the document page by page from the tray 142 of thedocument feeder 141 and performs a document read operation (hereinafter,such an operation mode will be referred to as a document feeding-readingmode). Further, the document may be read in such a way that the userplaces the document on the document positioning glass plate to bedescribed below.

A printer 120 is an image forming device which forms the image datareceived from the controller 200 on a sheet.

According to the present exemplary embodiment, an electrophotographicmethod using a photosensitive drum, a developing device, and a fixingdevice is employed as an image forming method. More specifically, tonerattached on the drum is transferred to and fixed on the sheet. Further,the printer 120 includes a plurality of sheet cassettes 121, 122, and123 capable of corresponding to different sheet size and sheetorientation. A printed sheet is discharged to a sheet discharge tray124. If an abnormality, such as deterioration and failure, occurs in theabove-described scanner 140 and the printer 120, the abnormality mayappear in the scanned image and the print image.

<Image Forming Apparatus: Scanner Unit>

FIG. 3 is a schematic diagram illustrating a main configuration of thescanner 140 employing the linear image sensor and the reading operationperformed thereby according to the present exemplary embodiment. Inparticular, FIG. 3 is the schematic diagram illustrating the mainconfiguration of the scanner 140 and the reading operation performedwhen the operation mode is the “document feeding-reading” mode in whichthe document is read by activating the document feeder 141.

Referring to FIG. 3, a document stack 100P to be read is placed on thetray 142. Further, a feed roller 1411, a separation-conveyance roller1412, and a registration roller 1413 are disposed downstream to adocument conveying direction. The feed roller 1411 is rotated by adriving source (not illustrated) and feeds the document stack 100Pplaced on the tray 142. The separation-conveyance roller 1412 disposeddownstream of the feed roller 1411 then separates and conveys a topdocument 100 from the conveyed document stack 100P. Starting of rotationof the registration roller 1413 arranged downstream of theseparation-conveyance roller 1412 becomes criterion for a subsequentconveyance timing and an image reading timing of the document 100.

An example of the driving source of the feed roller 1411, theseparation-conveyance roller 1412, and the registration roller 1413 is astepping motor.

The document 100 fed by the registration roller 1413 moves along aguiding plate 1418 and is held by a rotating large-diameter conveyancedrum 1415 and driven rollers 1416 a, 1416 b, and 1416 c. The document100 is thus conveyed along an outer periphery of the conveyance drum1415. In the above-described process, the document 100 once passes overa surface of a document positioning glass plate 1401 and is conveyed atconstant speed in a direction of an arrow illustrated in FIG. 3.

When the document 100 passes over the surface of the documentpositioning glass plate 1401, the image reading unit to be describedbelow performs image reading to the document 100.

After the image has been read, the document 100 is continuously conveyedalong the outer periphery of the conveyance drum 1415 and is dischargedto the document feeder 141 by a discharge roller 1417.

In the above-described document feeding-reading mode, it is onlynecessary to move the document in a fixed direction, so that a largeamount of documents can be continuously read at high speed.

The image reading unit according to the present exemplary embodimentwill be described below. In the document feeding-reading mode, thedocument 100 passes over the surface of the document positioning glassplate 1401 as described above. In the above-described process, a firstmirror unit 1409 and a second mirror unit 1410 are moved by a motor 1408and fixedly-arranged in the positions illustrated in FIG. 3. As aresult, when the document 100 faces the surface of the documentpositioning glass plate 1401, an illumination lamp 1402 in the firstmirror unit 1409 irradiates the document 100. The reflected lightthereof is then focused on a CCD sensor 1407 by a lens 1406 via mirrors1403, 1404, and 1405. The reflected light input to the CCD sensor 1407is converted to the electric signal, and an analog/digital (A/D)conversion unit (not illustrated) converts the electric signal of eachpixel to digital data. The converted digital data is then input to thecontroller 200 as a pixel signal.

The above-described method uses a cylindrical light source, and areading line is set parallel to a longitudinal direction of the lightsource. The document is conveyed in a direction perpendicular to thereading line. The direction parallel to the reading line is defined as amain scanning direction, and a direction perpendicular to the readingline (a document conveying direction) is defined as a sub-scanningdirection.

Further, there is a method for reading the image by placing the documentto be read on the document positioning glass plate 1401 instead of thedocument feeding-reading mode. In such a case, the first mirror unit1409 including the mirror 1403 and the illumination lamp 1402 moves at aspeed v below the document positioning glass plate 1401 on which thedocument is placed. Further, the second mirror unit 1410 including themirrors 1404 and 1405 moves at a speed 1/2 v in the same direction asthe first mirror unit 1409 and thus scans a front side of the document100. The first mirror unit 1409 and the second mirror unit 1410 aredriven by the motor 1408.

According to the present exemplary embodiment, scan transmission ofanalysis charts to be described below is performed while the document isread in the document feeding-reading mode.

<Abnormal Image Occurrence in Scanning>

FIG. 4 is a diagram illustrating an example in which dust hasaccumulated on the document positioning glass plate 1401. When the imageforming apparatus according to the present exemplary embodiment whichincludes an auto document feeding device reads a document in theabove-described document feeding-reading mode, the image formingapparatus reads the dust adhered on the document positioning glass plate1401. A streak is thus generated in the read image. Such a streak isgenerated due to the dust accumulating on the document positioning glassplate 1401 between the first mirror unit 1409 and the conveyance drum1415 (an intersection between the document positioning glass plate 1401and a dotted line illustrated in FIG. 4). Since the streak is generateddue to the accumulation of dust and is not an image drawn on thedocument, there is no correlation between the streak and surroundingpixels in the document.

FIG. 5 is a diagram illustrating an example of the read image when thedust adheres to the document positioning glass plate 1401. Referring toFIG. 5, the image includes a black streak (abnormal pixels). The blackstreak appears with width in a specific position in the main scanningdirection due to the effect of the dust when the documentfeeding-reading operation is performed, and extends as a streak in thesub-scanning direction. In such a case, the streak adversely affectsscanning of the analysis chart used for analyzing the cause of theabnormal image and transmission of the image data obtained by scanningthe analysis chart to be described below.

Hereinafter, the image data obtained by scanning the image or the chartwill be referred to as scanned image data.

<Image Forming Apparatus: Controller>

FIG. 6 is a block diagram illustrating a hardware configuration of theimage forming apparatus according to the present exemplary embodiment,and in particular, a configuration example of the controller in detail.

The controller 200 is coupled to the scanner 140, which is an imageinput device, the printer 120, which is an image output device, the LAN10, and a public line (a wide area network (WAN)) 11. The controller 200collectively controls operations of the image forming apparatus andcontrols input and output of image information and device information.

A central processing unit (CPU) 2100 is a processor which controls anentire image forming apparatus and collectively controls access betweenthe image forming apparatus and the various connected devices based on acontrol program stored in a read-only memory (ROM) 2120. Further, theCPU 2100 collectively controls various processes performed in thecontroller 200. A random access memory (RAM) 2110 is a system workmemory used for the CPU 2100 to operate, and is also an image memory fortemporarily storing the image data. The ROM 2120 is a boot ROM whichstores a boot program of the system. A hard disk drive (HDD) 2130 mainlystores image data and information necessary for activating and operatinga computer (system software). Instead of using the HDD 2130, such datamay be stored in a recording medium capable of holding the stored dataeven when the power is turned off.

A LAN controller (LANC) 2200 connects to the LAN 10 and inputs andoutputs image data to be output and the information related to devicecontrol to and from a personal computer (PC, not illustrated) of a user.Further, the LANC 2200 inputs and outputs data on an abnormal image toand from the image inspection apparatus 110 to be described below. Amodem 2210 connects to the public line 11 and inputs and outputs data.

A printer interface (IF) image processing unit 2300 connects to theprinter 120 and communicates with a CPU included in the printer 120.Further, the printer IF image processing unit 2300 performs imageprocessing, such as halftone processing, for printing and outputting theimage data. A scanner IF image processing unit 2400 connects to thescanner 140 including the document feeder 141 and communicates with aCPU included in the scanner 140. Further, the scanner IF imageprocessing unit 2400 performs image processing, such as shadingcorrection processing, for scanning and inputting the image data.

A raster image processor (RIP) 2500 rasterizes image data (in a pagedescription language (PDL) code) received from an external user PC viathe LAN 10 to bitmap data.

An operation unit IF 2600 outputs the image data to be displayed on theoperation unit 160 from the controller 200 to the operation unit 160.Further, the operation unit IF 2600 outputs the information input to theoperation unit 160 by the user of the image forming apparatus to thecontroller 200.

<Abnormal Image Occurrence in Printing>

FIG. 7 is a diagram illustrating concrete examples of image problemsoccur in the output image, when printing is performed using the imageforming apparatus. In a dust problem image 301, a small smudge 302adheres to an output image. In a streak problem image 303, a streak 304appears in a vertical direction or a horizontal direction of the image.In an unevenness problem image 305, spotted and linear abnormalities 306are visible in the entire image. Further, there are image problems interms of color and a toner scattering problem mainly occur to thin linesdue to heat of the fixing device (not illustrated). The above-describedimage problems are representative examples, and other image problemswhich the user considers as abnormal occur due to various causes in theimage forming apparatus 103. Such image problems are caused byabnormalities (failure and deterioration) of various components, such asthe photosensitive drum, the developing device, and the fixing devicewhich are used for realizing image formation by the electrophotographicmethod in the printer 120. Further, such problems can be largelyclassified according to a size of an occurrence location of the problem(hereinafter referred to as a problematic location) and a position atwhich the problem occurs in the image. More specifically, the problemsare classified according to whether the problematic location is large orsmall, and whether the position at which the problem occurs is theentire image or a portion of the image. In the dust problem image 301,the problematic location is small and the position at which the problemoccurs is a portion of the image. In the unevenness problem image 305,the problematic location is large and the position at which the problemoccurs is the entire image. In the streak problem image 303, theproblematic location is small (or thin) and the position at which theproblem occurs is the entire image in only one of the vertical directionor the horizontal direction of the image.

It is thus necessary to reproduce the image problem for analyzing thecause of the image abnormality. An image required for such areproduction will be described below. In the case of the dust problemimage 301, the occurrence location cannot be identified, and theproblematic location is small, so that it becomes necessary to analyzethe entire image for identifying the image problem. However, in the caseof the streak problem image 303, the problem certainly appears byviewing the image in the horizontal direction. Further, in the case ofthe unevenness problem image 305, the problem occurs in the entireimage, so that the problem appears even if only a portion of the imageis viewed. The size and type of the image necessary for performinganalysis are thus different depending on a type of an image problem inan image to be detected.

According to the present exemplary embodiment, the printer unit 120 orthe printer IF image processing unit 2300 in the image forming apparatusaccording to the present exemplary embodiment includes a function foroutputting an analysis chart when such an image problem occurs. Theanalysis chart is an image for reproducing the problem.

A type of the chart to be used in the analysis is determined accordingto the type of the image problem to be detected.

The image forming apparatus outputs the analysis chart in which theimage problem is reproduced, reads the analysis chart using the scanner140 and the document feeder 141, and transmits the read image data tothe image inspection apparatus 110 on the network via the LANC 2200.

<Image Inspection Apparatus: Hardware Configuration>

FIG. 8 illustrates an example of the hardware configuration of the imageinspection apparatus 110. The image inspection apparatus 110 includes aCPU 1101, a RAM 1102, a ROM 1103, an HDD 1104, a network unit 1107, aninput/output (IO) unit 1105, and an operation unit 1106 which areconnected to each other by a system bus 1108.

The CPU 1101 reads programs, such as an operating system (OS) andapplication software, from the HDD 1104 to execute the programs and thusprovides various functions. Further, the CPU 1101 collectively controlsan image inspection process performed by the image inspection apparatus110. The RAM 1102 is a system work memory used when the CPU 1101executing the programs. The ROM 1103 stores programs for activating abasic input/output system (BIOS) and the OS, and setting files. The HDD1104 stores system software and a program for realizing the imageinspection process to be described below. The program is stored in astorage medium and distributed, or downloaded from a server (notillustrated) connected via the LAN 10, and installed in the HDD 1104.The network unit 107 is connected to the LAN 10 and communicates(performs transmission and reception) with external devices, such as theimage forming apparatuses 101, 102, and 103. The IO unit 1105 is aninterface for inputting and outputting information to and from theoperation unit 1106 which includes a liquid crystal display and aninput/output device (not illustrated), such as a mouse. Predeterminedinformation is displayed on the liquid crystal display at predeterminedresolution and a predetermined color number based on screen informationinstructed by the program. For example, a graphical user interface (GUI)screen is formed on the liquid crystal display, and various windows anddata necessary for operating the image inspection apparatus 110 isdisplayed.

<Image Inspection Apparatus: Configuration of Image Inspection Function>

FIG. 9 is a diagram illustrating an example of an image inspectionprogram 1110 executed by the image inspection apparatus 110. The imageinspection program 1110 is stored in the HDD 1104 as a function to berealized by the image inspection apparatus 110. The image inspectionprogram 1110 is read from the HDD 1104 to the RAM 1102 by the CPU 1101executing the boot program. The CPU 1101 then executes the program readinto the RAM 1102.

An image analysis unit 1111 implemented by the image inspection program1110 executed by the image inspection apparatus 1110 will be describedbelow along with examples of charts necessary for performing theanalysis. FIG. 10 is a diagram illustrating concrete examples of thecharts. A solid chart 401 is an example of a chart uniformly filled withthe same color. The solid chart 401 is effective for analyzing the dustproblem image 301, the streak problem image 303, and the unevennessproblem image 305 which are abnormal images generated when printing. Theimage forming apparatus 103 includes the photosensitive drum, thedeveloping device, and the fixing device (not illustrated), andgenerates a printed product by transferring toner attached to the drumto a sheet and fixing the transferred toner on the sheet. The imageforming apparatus 103 may include the drums for each of cyan (C),magenta (M), yellow (Y), and black (K) colors, or may include one drumwhich corresponds to all colors. In the case of the image formingapparatus 103 including four drums, the image problem may occur in onlya specific color, so that the solid chart 401 is required for eachcolor. Density of the solid chart 401 is not limited thereto, and ismatched to a density range in which the image problem is easilydetectable.

The density range in which the image problem is easily detectable willbe described in detail below.

For example, a case where the image problem to be detected is the dustproblem image 301 will be described below. It is highly likely that thedensity of image data of a dust (smudged) portion read together with theanalysis chart in scanning is the maximum density. Accordingly, it isdesirable for the density of the solid chart 401 to be intermediatedensity instead of the maximum density so that the image data of thedust (smudged) portion becomes more noticeable as compared to thesurroundings.

On the other hand, if the streak problem image 303 is to be detected, itis desirable for the density of the solid chart 401 to be high fordetecting a streak of low density.

As described above, it is necessary to change the density of the solidchart 401 according to the density of the problematic portion of theimage problem to be detected. The solid chart 401 may thus be one solidchart having densities corresponding to all problematic images to bedetected, or may be a plurality of solid charts if one chart cannotcorrespond to all densities.

It is assumed that there is a plurality of image problems. In such acase, the solid chart formed of a plurality of densities may becomenecessary. A thin line chart 402 is an example of a chart in which thinlines are drawn for detecting the scattering problem described above.The images included in the thin line chart 402 is not limited to thethin lines, and may be small characters, as long as a problem unique tothin drawings can be analyzed. The thin line chart 402 is thus notlimited thereto. A color patch chart 403 is an example of a chart to beused in analyzing the color problem. Patches 404 included in the colorpatch chart 403 are single color patches and mixed color patches whichare aligned as necessary. If uniformity of the color in the verticaldirection or the horizontal direction is to be analyzed, it is necessaryto align the color patches 404 of the same color in the verticaldirection or the horizontal direction.

When analysis is performed using the solid chart 401, it is necessary todetermine whether there is a portion in which a feature amount isdifferent from the surroundings in the entirely uniform image.

For example, a histogram of signal values of scanned image data of thesolid chart 401 in which the image abnormality has occurred in printingis obtained as a feature amount. The histogram is then compared with ahistogram of the scanned image data of the solid chart 401 in which theimage abnormality has not occurred in printing, and the analysis isperformed using the difference. Further, frequency analysis on thescanned image data of the solid chart 401 may be similarly performed foranalyzing whether a component other than a direct-current component isdetected.

When analysis is performed using the thin line chart 402, it isnecessary to determine whether there is scattering or bleeding aroundthe thin lines in the output thin line chart 402. For example,surroundings of the thin line to be analyzed is minutely viewed andcompared with scanned image data of the thin line chart 402 which isoutput when the abnormal image has not been generated, and thedifference is determined. For example, a thin line area is detected fromthe scanned image data of the thin line chart 402 using edge detectionand conventional black character determination. Rounding of the edge anda change in the color from paper white due to scattering of the toner onthe paper white around the edge are then analyzed.

When analysis is performed using the color patch chart 403, a pixelvalue of each patch 404 included in scanned image data of the colorpatch chart 403 is obtained. Generally, the pixel values of a small areain the patch 404 is averaged and set as the pixel value of the patch.

The obtained pixel value is then compared with a pixel value of thepatch in scanned image data of the color patch chart 403 which is outputwhen it has been determined that the abnormal image has not beengenerated, and the difference is analyzed. Further, if the same colorpatches 404 are arranged in the color patch chart 403, the pixel valuesof the patches 404 in the scanned image data are compared, and theuniformity within a surface is analyzed.

A chart analysis result obtained by each of the above-described analysismethods is calculated as the feature amount and used by a printerabnormality location estimation unit 1113 to be described below.

The above-described methods are only examples of the analysis method,and any method may be employed as long as the image problem to beinspected can be appropriately analyzed.

Further, blank paper scan data which is a result obtained by scanning ablank document is used for calculating the feature amount, similarly asthe chart analysis, for confirming an abnormality location in thescanner to be described below.

According to the present exemplary embodiment, the blank paper is adocument which does not include printed information.

More specifically, the blank paper is used for identifying, in a casewhere a pixel which is not a white pixel is included in scanned imagedata obtained by reading the originally blank paper, the pixel as anabnormal pixel. The calculated feature amount is used in a scannerabnormality location estimation unit 1112 to be described belowsimilarly as the chart analysis.

According to the present exemplary embodiment, the abnormality locationin the scanner and the abnormality location in the printer areseparately identified using a feature amount calculated by the imageanalysis unit 1111 and a database as an example of an abnormalitylocation estimation process.

The database is a database in which the feature amount is associatedwith the actual abnormality location based on result data.

More specifically, the database, in the printer abnormality locationestimation unit 1113, is a collection of data on the abnormalitylocations, such as the fixing device, the developing device, and thephotosensitive drum, and feature amounts which have been obtained in thepast when the abnormalities have occurred in such components. Further,the database, in the scanner abnormality location estimation unit 1112,is a collection of data on smudge and scratching of the documentpositioning glass plate, smudge of the mirror in the mirror unit, andthe abnormality in the CCD sensor, and feature amounts which have beenobtained in the past when such abnormality have occurred.

Since frequency feature amounts and color feature amounts arerespectively calculated according to the above-described frequencyanalysis and color analysis, there may be a plurality of databases. Animage feature amount may be calculated from a plurality of featureamounts, and the database may be generated. Further, the database may beindependently managed for each of the image forming apparatuses 101,102, and 103, or there may be one collective database. For example, ifthe image forming apparatuses 101, 102, and 103 are the same models, andthere is commonality in a relation between the abnormality location inwhich the abnormality has occurred and the feature amount obtained whenthe abnormality has occurred, the database may be collectivelygenerated. However, if there is no commonality in the relation betweenthe abnormality location in which the abnormality has occurred and thefeature amount obtained when the abnormality has occurred even if theimage forming apparatuses 101, 102, and 103 are the same models, thedatabases are separately generated.

Further, the database may be generated using data previously predictedwhen designing the apparatus, or data of previous products as well asresults obtained by the service person.

A Bayes' expansion formula may be used as a method for estimating theabnormality location from the database and the obtained feature amount.The Bayes' expansion formula is a general formula for calculating aprobability of obtaining certain data (the feature amount according tothe present exemplary embodiment) from the cause (the abnormalitylocation according to the present exemplary embodiment). Further, othermethods may be used as long as the abnormality location can beestimated.

According to the present exemplary embodiment, the image inspectionapparatus 110 calculates the feature amount. However, the image formingapparatus (100, 101, or 102) may calculate the feature amount andtransmit the calculated feature amount to the image inspection apparatus110. Other server (not illustrated) may be used for calculating thefeature amount and estimating the abnormality location.

According to the present exemplary embodiment, the scanned image isobtained using the scanner 140. However, a value obtained using othermeasurement device or a value calculated from the obtained value may beused as the feature amount.

<Flowchart of Process Performed by Image Forming Apparatus>

FIG. 11 is a flowchart illustrating a process performed by the imageforming apparatus according to the present exemplary embodiment. The CPU2100 executes the process of the flowchart illustrated in FIG. 11according to the program stored in the HDD 2130. The process isperformed for reproducing, using the analysis chart, the abnormal imagecaused by the abnormality which has occurred in the image formingapparatus and transmitting the reproduced abnormal image to the imageinspection apparatus 110.

If the abnormal image is generated when the image forming apparatusperforms printing, the user of the image forming apparatus executes theprocess of the flowchart illustrated in FIG. 11.

In step S101, the CPU 2100 obtains information on the analysis chartindicating what type of chart will be output. There is a plurality ofanalysis charts according to the objective of the analysis as describedwith reference to FIG. 10.

In step S102, the CPU 2100 outputs the analysis chart prepared in stepS101. More specifically, the CPU 2100 transfers and fixes a tonerattached to the drum (not illustrated) in the image forming apparatus toa sheet by using the printer 120. As a result, the analysis chart isprinted on the sheet and output from the sheet discharge tray 124. Asdescribed above, if the image abnormality, such as streaks orunevenness, has occurred due to the abnormality in the printer, theimage abnormality occurs in the printed analysis chart.

In step S103, the CPU 2100 displays an instruction to scan the analysischart output in step S102 and the blank paper on the display unit (notillustrated) in the operation unit 160. More specifically, the CPU 2100displays “Insert blank paper to top page of printed charts, and setcharts and blank paper facing upwards on document feeder. After setting,press document read start button.” The instruction may be displayedusing diagrams and graphics as long as the user becomes capable ofcorrectly setting the analysis charts and the blank paper on thedocument feeder 141. Further, if the image forming apparatus includes aunit for determining whether a first page of the documents to be scannedis the blank paper, such a unit may be used to determine whether thereis the blank paper. If the unit determines that there is no blank paper,the CPU 2100 may display a warning prompting the user to insert theblank paper on the display unit in the operation unit 160.

In step S104, upon receiving the scan instruction from the user, the CPU2100 scans the documents (the blank paper and the analysis charts)placed on the document feeder 141. The scanner 140 performs scanningusing the document feeding-reading mode. The scanner IF image processingunit 2400 then appropriately performs image processing on the scannedimage data obtained by scanning the documents, and the processed data isstored in the HDD 2130. As described above, when the scanner 140 scansthe documents in the document feeding-reading mode, the imageabnormality, such as a streak, may occur in the scanned image data. Theimage abnormality may thus be further superimposed on the scanned imagedata of the analysis chart in which the image abnormality has occurredin printing.

In step S105, the CPU 2100 transmits the scanned image data of theanalysis charts and the blank paper read in step S104 and stored in theHDD 2130 to the image inspection apparatus 110. More specifically, theCPU 2100 transmits the data to the image inspection apparatus 110connected to the LAN 10 via the LANC 2200.

By the above-described process, the scanned image data of the analysischarts and the blank paper in which the image abnormality that hasoccurred in the image forming apparatus is reproduced is transmitted tothe image inspection apparatus 110.

<Flowchart of Image Inspection Process Performed by Image InspectionApparatus>

FIG. 12 is a flowchart illustrating the image inspection processperformed by the image inspection apparatus 110 according to the presentexemplary embodiment. The CPU 1101 executes the process of the flowchartillustrated in FIG. 12 according to the program stored in the HDD 1104.The process is performed for identifying the cause of the abnormal imagegenerated by the image forming apparatus.

In step S201, the CPU 1101 receives the scanned image data obtained byscanning the analysis charts and the blank paper from the image formingapparatus. The scanned image data is the data transmitted from the imageforming apparatus in step S105 of the flowchart illustrated in FIG. 11.If CPU 1101 receives the scanned image data obtained by scanning theanalysis charts and the blank paper (YES in step S201), the processproceeds to step S202.

In step S202, the CPU 1101 analyzes the blank paper scanned image dataobtained by scanning the blank document among the received scanned imagedata. More specifically, such an analysis is a function of the imageanalysis unit 1111, and the image analysis unit 1111 calculates thefeature amount using the blank paper scanned image data for confirmingthe abnormality location in the scanner. As described above, the featureamount is for identifying, if a pixel which is not a white pixel isincluded in the image data obtained by scanning the blank paper, thepixel as the abnormal pixel. Further, the analysis result is calculatedas the feature amount similarly as when the chart analysis is performed.

In step S203, the CPU 1101 determines whether a scanner abnormality hasbeen detected as a result of analyzing the blank paper in step S202. Thescanner abnormality is a failure which has occurred in scan processingperformed by the image forming apparatus in step S104 illustrated inFIG. 11. The CPU 1101 performs the determination based on whether thereis an abnormal pixel included in the blank paper scanned image data. Ifthe CPU 1101 determines that the abnormality is detected (YES in stepS203), the process proceeds to step S204. If the CPU 1101 determinesthat the abnormality is not detected (NO in step S203), the processproceeds to step S206.

In step S204, the CPU 1101 estimates the abnormality location in thescanner according to the function of the scanner abnormality locationestimation unit 1112. As described above, the abnormality location inthe scanner is estimated by using the Bayes' expansion formula based onthe feature amount obtained in step S202. The abnormality to beestimated includes the abnormality of the CCD sensor which requiresreplacement the component. Further, the abnormality to be estimatedincludes smudge of the document positioning glass plate or smudge of themirror in the mirror unit, which requires cleaning instead ofreplacement of the component. The service person performing maintenanceand inspection of the image forming apparatus thus becomes capable ofdetermining, using the image inspection apparatus 110, the cause of theimage abnormality which has occurred in the scanner unit in the imageforming apparatus from a remote location. Further, the service personbecomes capable of determining the measures (replacing or adjusting thecomponent, or clean the component). As a result, the downtime necessaryfor solving the image abnormality can be reduced as compared to theconventional downtime.

In step S205, the CPU 1101 determines whether the abnormality which hasbeen determined to have occurred in step S202 affects the printeranalysis. More specifically, the CPU 1101 determines whether theabnormal pixel included in the blank paper scanned image data affectsextraction of the feature amount when performing the chart analysis. Forexample, the image abnormality may be the streak generated due to thedust adhered at the reading position when scanning is performed in thedocument feeding-reading mode. In such a case, it is difficult todistinguish the image abnormality from the image abnormality of a streakgenerated due to smudge or abnormality in the printer 120. The imageabnormality may thus be misrecognized as the abnormality which hasoccurred due to the printer 120. In such a case, the CPU 1101 determinesthat the abnormality affects the printer analysis (YES in step S205),and the process proceeds to step S207. On the other hand, if theabnormal pixel is outside of the range to be used for analyzing thechart, the CPU determines the abnormality does not affect the printeranalysis (NO in step S205), and the process proceeds to step S206.

In step S206, the CPU 1101 analyzes the charts received from the imageforming apparatus. The CPU 1101 thus extracts the feature amountnecessary for estimating the abnormality location in the printer 120.The process performed in step S206 will be described in detail below.

In step S207, the CPU 1101 analyzes the charts received from the imageforming apparatus while reducing the effect of the abnormal pixel due tothe scanner. As a result, the CPU 1101 becomes capable of extracting thefeature amount necessary for estimating the abnormality location in theprinter 120 even if the scanned image data of the analysis chartincludes the abnormal pixel due to the scanner. The process performed instep S207 will be described in detail below.

In step S208, the CPU 1101 estimates the abnormality location in theprinter according to the function of the printer abnormality locationestimation unit 1113. As described above, the abnormality location inthe scanner is estimated by using the Bayes' expansion formula based onthe feature amount obtained in step S206 or step S207. The abnormalityto be estimated includes the abnormality of the developing device, thephotosensitive drum, and the fixing device which are componentsnecessary for printing. The service person performing the maintenanceand the inspection of the image forming apparatus thus becomes capableof determining, using the image inspection apparatus 110, the cause ofthe image abnormality which has occurred in the printer unit in theimage forming apparatus from a remote location. Further, the serviceperson becomes capable of determining the measures (replacing oradjusting the component, or cleaning the component). As a result, thedowntime required for solving the image abnormality can be reduced ascompared to the conventional downtime.

<Flowchart of Chart Analysis Process>

FIG. 13 is a flowchart illustrating a chart analysis process performedby the image inspection apparatus 110 according to the present exemplaryembodiment. FIG. 13 illustrates in detail the process of step S206illustrated in FIG. 12. The CPU 1101 executes the process of theflowchart illustrated in FIG. 13 according to the function of the imageanalysis unit 1111 in the image inspection program 1110 stored in theHDD 1104.

In step S301, the CPU 1101 determines whether real space analysis, whichis an analysis method, is to be performed, based on the type of theanalysis chart. In other words, the CPU 1101 determines based on whetherthe analysis chart corresponding to currently-focused scanned image datarequires the real space analysis to be performed.

If the CPU 1101 determines that the real space analysis is to beperformed (YES in step S301), the process proceeds to step S302. If theCPU 1101 determines that the real space analysis is not to be performed(NO in step S301), the process proceeds to step S303. In step S302, theCPU 1101 performs the real space analysis to all pixels. For example,the CPU 1101 obtains a histogram of the signal values of all pixels inthe scanned image data of the analysis chart. The CPU 1101 then comparesthe obtained histogram with a histogram obtained from thepreviously-stored scanned image data of the analysis chart that has beenoutput when it has been determined that there is no image abnormality.The CPU 1101 extracts the difference as the feature amount.

In step S303, the CPU 1101 then determines whether to perform thefrequency analysis, which is an analysis method, based on the type ofthe analysis chart. The CPU 1101 determines based on whether theanalysis chart corresponding to the currently-focused scanned image datarequires the frequency analysis to be performed. If the CPU 1101determines that the frequency analysis is to be performed (YES in stepS303), the process proceeds to step S304. If the CPU 1101 determinesthat the frequency analysis is not to be performed (NO in step S303),the process proceeds to step S306.

In step S304, the CPU 1101 extracts a frequency analysis area. Morespecifically, the CPU 1101 extracts the analysis area of a size, such as512×512 pixels, from the scanned image data of the analysis chart. Theextracted area is basically square-shaped, and the size is determined sothat the feature of the cause of the image abnormality to be detectedcan be easily extracted. The CPU 1101 may extract a plurality of areasaccording to the occurrence of the image abnormalities and repeatedlyperform the frequency analysis. The CPU 1101 may automatically performthe area extraction, or the user may indicate the extraction area fromthe operation unit 1106 in the image inspection apparatus 110 whichincludes the input/output devices, such as the liquid crystal displayand the mouse.

In step S305, the CPU 1101 performs the frequency analysis on the areaof the scanned image data of the analysis chart extracted in step S304.For example, a result of whether the component other than thedirect-current component is detected by the frequency analysis may beextracted as the feature amount.

In step S306, the CPU 1101 determines whether to perform the coloranalysis, which is an analysis method, based on the type of the analysischart. The CPU 1101 determines based on whether the analysis chartcorresponding to the currently-focused scanned image data (for example,the color patch chart) requires the color analysis to be performed. Ifthe CPU 1101 determines that the color analysis is to be performed (YESin step S306), the process proceeds to step S307. If the CPU 1101determines that the color analysis is not to be performed (NO in stepS306), the process ends.

In step S307, the CPU 1101 performs the color analysis on the patch areain the analysis chart. For example, the CPU 1101 uses a pixel value ofthe patch obtained by averaging the pixel values in a small area in thepatch among the scanned image data of the analysis chart. The CPU 1101then obtains the feature amount from the difference between the obtainedpixel value and a pixel value of the patch included in the scanned imagedata of the analysis chart that has been output when it has beendetermined that there is no abnormal image. Further, if the same colorpatches are arranged in the analysis chart, the CPU 1101 compares pixelvalues of the patches and extracts uniformity within a plane as thefeature amount.

The chart analysis process performed by the image inspection apparatus110 is as described above.

<Flowchart of Chart Correction and Analysis Process>

FIG. 14 is a flowchart illustrating a chart correction and analysisprocess performed by the image inspection apparatus 110 according to thepresent exemplary embodiment. FIG. 14 illustrates in detail the processof step S207 illustrated in FIG. 12. The CPU 1101 executes the processof the flowchart illustrated in FIG. 14 according to the function of theimage analysis unit 1111 in the image inspection program 1110 stored inthe HDD 1104.

In step S401, the CPU 1101 determines whether the real space analysis,which is an analysis method, is to be performed. If the CPU 1101determines that the real space analysis is to be performed (YES in stepS401), the process proceeds to step S402. If the CPU 1101 determinesthat the real space analysis is not to be performed (NO in step S401),the process proceeds to step S403.

In step S402, the CPU 1101 eliminates a pixel corresponding to theabnormal pixel caused by scanning in the scanned image data of theanalysis chart, and performs the real space analysis.

For example, it is assumed that the abnormality such as the streakillustrated in FIG. 5 has occurred in the analysis chart due to theabnormality in the scanner 140 in the image forming apparatus. In such acase, the streak as illustrated in FIG. 5 is also generated in thescanned image data of the blank paper. The CPU 1101 thus generatesscanned image data in which pixels in the scanned image data of theanalysis chart at position corresponding to the abnormal pixels detectedin the scanned image data of the blank paper is eliminated. The CPU 1101then obtains a histogram of the signal values of the generated scannedimage data. As a result, only the abnormality which has occurred in theprinter 120 in the image forming apparatus is reflected in thehistogram. The CPU 1101 then compares the obtained histogram with thehistogram obtained from the previously-stored scanned image data of theanalysis chart that has been output when it has been determined thatthere is no image abnormality. The CPU 1101 extracts the difference asthe feature amount.

In step S403, the CPU 1101 determines whether to perform the frequencyanalysis, which is an analysis method, similarly as performed in stepS303 illustrated in FIG. 13. If the CPU 1101 determines that thefrequency analysis is to be performed (YES in step S403), the processproceeds to step S404. If the CPU 1101 determines that the frequencyanalysis is not to be performed (NO in step S403), the process proceedsto step S406.

In step S404, the CPU 1101 extracts the frequency analysis area of thescanned image data of the analysis chart while avoiding the pixelcorresponding to the abnormal pixel caused by scanning to the scannedimage data of the analysis chart. For example, it is assumed that theabnormality such as the streak illustrated in FIG. 5 has occurred in theanalysis chart due to the abnormality in the scanner 140 in the imageforming apparatus. In such a case, the streak as illustrated in FIG. 5is also generated in the scanned image data of the blank paper. The CPU1101 thus generates scanned image data in which the pixels in thescanned image data of the analysis chart at the position correspondingto the abnormal pixels detected in the scanned image data of the blankpaper is avoided. The CPU 1101 extracts the area to be analyzed of thesize, such as 512×512 pixels, from the image data. The extracted area isbasically square-shaped, and the size is determined so that the featureof the cause of the image abnormality to be detected can be easilyextracted. Further, the CPU 1101 may extract a plurality of areasaccording to the occurrence of the image abnormalities and repeatedlyperform the frequency analysis.

The CPU 1101 may automatically perform the area extraction so as toavoid the abnormal pixel due to abnormality of the scanner 140, or theuser may indicate the extraction area from the operation unit 1106 inthe image inspection apparatus 110 which includes the input/outputdevices, such as the liquid crystal display and the mouse. In such acase, the CPU 1101 performs adjustment so that the user cannot selectthe abnormal pixel positions on the liquid crystal display.

In step S405, the CPU 1101 performs the frequency analysis on the areaof the scanned image data of the analysis chart extracted in step S404,similarly as performed in step S305 in the flowchart illustrated in FIG.13. If the CPU 1101 performs, when performing the frequency analysis,correction such as linear interpolation of the abnormal pixel andincludes the abnormal pixel in the extracted area of the frequencyanalysis, the CPU 1101 may obtain a frequency component due to theinterpolation which is not originally to be extracted. It is thusappropriate to avoid the abnormal pixel detected in step S204 of theflowchart illustrated in FIG. 12.

In step S406, the CPU 1101 then determines whether to perform the coloranalysis, which is an analysis method, similarly as performed in stepS306 in the flowchart illustrated in FIG. 13. If the CPU 1101 determinesthat the frequency analysis is to be performed (YES in step S406), theprocess proceeds to step S407. If the CPU 1101 determines that thefrequency analysis is not to be performed (NO in step S406), the processends.

In step S407, the CPU 1101 performs interpolation of the pixelcorresponding to the abnormal pixel caused by scanning to the scannedimage data of the analysis chart. For example, it is assumed that theabnormality, such as the streak illustrated in FIG. 5, has occurred inthe analysis chart due to the abnormality in the scanner 140 in theimage forming apparatus. In such a case, the streak as illustrated inFIG. 5 is also generated in the scanned image data of the blank paper.The CPU 1101 thus corrects the pixel in the scanned image data of theanalysis chart at the position corresponding to the abnormal pixeldetected in the scanned image data of the blank paper, using thesurrounding pixels of the pixel.

In other words, the CPU 1101 performs linear interpolation usinghorizontally-adjacent pixels of the abnormal pixel included in thescanned image data, and replaces the abnormal pixel with the calculationresult of the linear interpolation.

In step S408, the CPU 1101 performs the color analysis on the patch areain the analysis chart, similarly as performed in step S307. Since it isdifficult to extract the feature amount by avoiding the abnormal pixelin a small area, such as the patch, it is appropriate to performcorrection by interpolation.

The chart correction and analysis process is as described above.

The process performed in the flowchart illustrated in FIG. 14 isdifferent from the process performed in the flowchart illustrated inFIG. 13 as follows. The CPU 1101 appropriately selects eliminating,avoiding, or correcting a scan abnormal pixel according to the analysismethod for reducing the effect of the abnormal pixel caused by scanningon the chart analysis.

In other words, if the image forming apparatus scans the analysis chartand the image abnormality due to the abnormality in or the smudge of thescanner 140 occurs, a value obtained from the scanned image data of theanalysis chart is corrected by a value obtained from the scanned imagedata of the blank paper.

The abnormality location in the printer can thus be estimated using thecorrected value obtained from the scanned image data of the analysischart.

As a result, if the image forming apparatus scans the analysis chart andthe image abnormality due to the abnormality or the smudge of thescanner 140 occurs, the effect is reduced, and the abnormality in theprinter unit can be estimated by appropriately using the analysis chart.

According to the first exemplary embodiment, whether the abnormal pixelincluded in the scanned image data transmitted from the image formingapparatus is generated in the scanner 140 or the printer 120 isdetermined by inserting the blank paper. According to a second exemplaryembodiment, whether the abnormal pixel included in the scanned imagedata transmitted from the image forming apparatus is generated in thescanner 140 or the printer 120 is determined without inserting the blankpaper. Lowering of usability due to an insertion operation of the blankdocument can thus be reduced, as will be described below.

According to the present exemplary embodiment, the process performed bythe image forming apparatus is different from the process according tothe first exemplary embodiment. The hardware configurations of the imageforming apparatus and the image inspection apparatus are similar tothose according to the first exemplary embodiment. The differences fromthe first exemplary embodiment will be described in detail below.

<Flowchart of Process Performed by Image Forming Apparatus>

FIG. 15 is a flowchart illustrating the process performed by the imageforming apparatus according to the second exemplary embodiment. The CPU2100 executes the process of the flowchart illustrated in FIG. 15according to the program stored in the HDD 2130. The process isperformed for reproducing, using the analysis chart, the abnormal imagecaused by the abnormality which has occurred in the image formingapparatus and transmitting the reproduced abnormal image to the imageinspection apparatus. In other words, if the abnormal image is generatedwhen the image forming apparatus performs printing, the user of theimage forming apparatus executes the process.

In step S501, the CPU 2100 obtains information on the analysis chartindicating what type of chart will be output. There is a plurality ofanalysis charts according to the objective of the analysis as describedwith reference to FIG. 10.

In step S502, the CPU 2100 outputs the analysis chart prepared in stepS501. More specifically, the CPU 2100 uses the printer 120 and transfersthe toner attached to the drum (not illustrated) in the image formingapparatus to a sheet and fixes the transferred toner on the sheet. As aresult, the analysis chart is printed on the sheet and output from thesheet discharge tray 124. As described above, if the image abnormalitysuch as streaks or unevenness has occurred, the image abnormality occursin the printed analysis chart.

In step S503, the CPU 2100 displays an instruction to scan the analysischart output in step S502 on the display unit (not illustrated) in theoperation unit 160. More specifically, the CPU 2100 displays “Set theprinted charts on the document feeder facing upwards. After setting,press document read start button.” The instruction may be displayedusing diagrams and graphics as long as the user becomes capable ofcorrectly setting the analysis charts on the document feeder 141. TheCPU 2100 forcibly sets a document reading mode to a two-sided documentscan mode. Further, the CPU 2100 may display “set document read mode totwo-sided document mode” on the display unit in the operation unit 160and cause the user to set the document reading mode to the two-sideddocument scan mode.

In step S504, upon receiving the scan instruction from the user, the CPU2100 performs the two-sided scan of the document (the analysis charts)placed on the document feeder 141. The scanner 140 performs scanning inthe document feeding-reading mode. The scanner IF image processing unit2400 then appropriately performs image processing on the scanned imagedata obtained by scanning the documents, and the processed data isstored in the HDD 2130. As described above, when the scanner 140 scansin the document feeding-reading mode, the image abnormality may occurdue to the abnormality in the scanner 140. The image abnormality maythus be further superimposed on the scanned image data of the analysischart in which the image abnormality has occurred when the analysischart has been printed. According to the present exemplary embodiment,the CPU 2100 performs the two-sided scan, and the scanner 140 also scansa back side of the analysis chart. The back side is read for determiningwhether there is an abnormality occurring in the scanner 140. Accordingto the present exemplary embodiment, the analysis chart in which theback side is used in the two-sided scan is a document in which only oneside is printed. In other words, according to the present exemplaryembodiment, the image forming apparatus reads the back side which isblank, and the back side of the analysis chart is constantly blank. As aresult, the back side which is a white data side substitutes the blankpaper scanned according to the first exemplary embodiment. Inparticular, an effective result is obtained when applied to the imageforming apparatus which reads both the front side and the back sideusing the same image sensor.

In step S505, the scanned image data of the analysis chart read in stepS504 and stored in the HDD 2130 is transmitted to the image inspectionapparatus 110. The image data of the back side is also transmitted. Thedata is transmitted to the image inspection apparatus 110 connected tothe LAN 10 via the LANC 2200.

By performing the above-described process, the scanned image data of theanalysis chart and the back side in which the image abnormality that hasoccurred in the image forming apparatus is reproduced is transmitted tothe image inspection apparatus 110. The process illustrated in FIG. 15ends.

According to the first exemplary embodiment, the scanned image data ofthe blank paper is analyzed in step S202 in the process performed by theimage inspection apparatus 110 illustrated in the flowchart of FIG. 12.According to the second exemplary embodiment, the scanned image data ofthe image of the back side of the analysis chart is used in performingthe analysis. In such a case, the scanned image data of the back side ofthe analysis chart of the top page is taken as only one page of thescanned image data of the back side, and the result may be used inperforming analysis of all charts. Further, if the back sides of allanalysis charts are blank, the front side and the back side of theanalysis chart may be paired, and the analysis result of the scannedimage data of the back side may be used in the chart analysis of thefront side.

By performing the above-described process, whether the abnormal pixelincluded in the scanned image data transmitted from the image formingapparatus is generated in the scanner 140 or the printer 120 can bedetermined without inserting the blank paper. Lowering of usability dueto the insertion operation of the blank document can thus be reduced.

According to the present exemplary embodiment, the back side of theanalysis chart is scanned instead of scanning the inserted blank paper.However, the image data obtained by performing scanning before conveyingthe document (the image data obtained by reading a white color surfaceon the conveyance drum 1415) may be used instead of inserting the blankpaper. In such a case, the same result as inserting the blank paper canbe obtained.

Further, according to the first and second exemplary embodiments, theimage inspection apparatus 110 performs the image inspection process ofthe flowchart illustrated in FIG. 12. However, the CPU 2100 in the imageforming apparatus may perform the process according to the programstored in the HDD 2130.

Additional embodiments can also be realized by a computer of a system orapparatus that reads out and executes computer executable instructionsrecorded on a storage medium (e.g., computer-readable storage medium) toperform the functions of one or more of the above-describedembodiment(s), and by a method performed by the computer of the systemor apparatus by, for example, reading out and executing the computerexecutable instructions from the storage medium to perform the functionsof one or more of the above-described embodiment(s). The computer maycomprise one or more of a central processing unit (CPU), microprocessing unit (MPU), or other circuitry, and may include a network ofseparate computers or separate computer processors. The computerexecutable instructions may be provided to the computer, for example,from a network or the storage medium. The storage medium may include,for example, one or more of a hard disk, a random-access memory (RAM), aread only memory (ROM), a storage of distributed computing systems, anoptical disk (such as a compact disc (CD), digital versatile disc (DVD),or Blu-ray Disc (BD)™), a flash memory device, a memory card, and thelike.

While the present disclosure has been described with reference toexemplary embodiments, it is to be understood that these exemplaryembodiments are not seen to be limiting. The scope of the followingclaims is to be accorded the broadest interpretation so as to encompassall such modifications and equivalent structures and functions.

This application claims the benefit of Japanese Patent Application No.2013-241946 filed Nov. 22, 2013, which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. An apparatus comprising: an obtaining unitconfigured to obtain first image data obtained by reading, performed bya reading unit, a chart on which an image has not been formed by animage forming unit and second image data obtained by reading, performedby the reading unit, a chart formed by the image forming unit; and anestimation unit configured to change the second image data using thefirst image data and estimate a cause of an abnormality that hasoccurred in the image forming unit from a feature amount obtained byanalyzing the changed second image data.
 2. The apparatus according toclaim 1, wherein the estimation unit changes the second image data usingthe first image data based on a result of analyzing the first data. 3.The apparatus according to claim 1, wherein the estimation unit changes,in a case where it is determined that an abnormality has occurred in thereading unit according to the first image data, the second image datausing the first image data.
 4. The apparatus according to claim 1,wherein the estimation unit estimates a cause of an abnormality that hasoccurred in the image forming unit using data in which the featureamount is associated with the cause of the abnormality.
 5. The apparatusaccording to claim 1, wherein there is a plurality of types of chart anda type of chart is determined according to a type of abnormality thathas occurred in the image forming unit estimated by the estimation unit.6. The apparatus according to claim 1, wherein, in a case where it isdetermined that an abnormality has occurred in the reading unit as aresult of analyzing the first image data, a cause of the abnormality inthe reading unit is estimated using a feature amount obtained from aresult of analyzing the first image data.
 7. The apparatus according toclaim 1, wherein, in a case where it is determined that an abnormalityhas occurred in the reading unit as a result of analyzing the firstimage data and it is determined that the abnormality in the reading unitdoes not affect the apparatus, the second image data is not changed anda feature amount is obtained from the second image data.
 8. Theapparatus according to claim 1, wherein a method for changing the secondimage data using the first image data is different depending on a methodfor analyzing the second image data.
 9. The apparatus according to claim1, wherein the estimation unit eliminates, in a case where a method foranalyzing the second image data is real space analysis, performsestimation using a feature amount obtained by analyzing the second imagedata in which the pixel corresponding to an abnormal pixel included inthe first image data has been eliminated.
 10. The apparatus according toclaim 1, wherein the estimation unit eliminates, in a case where amethod for analyzing the second image data is frequency analysis,determines an area to be analyzed from the second image data in whichthe pixel corresponding to an abnormal pixel included in the first imagedata has been eliminated, and performs estimation using a feature amountobtained by analyzing the image data of the area.
 11. The apparatusaccording to claim 1, wherein the estimation unit interpolates, in acase where a method for analyzing the second image data is coloranalysis, performs estimation using a feature amount obtained byanalyzing the second image data in which an abnormal pixel included inthe first image data has been interpolated by pixels surrounding theabnormal pixel.
 12. The apparatus according to claim 1, wherein a chartin which an image has not been formed by the image forming unit is aback side of a chart used when obtaining the second image data.
 13. Theapparatus according to claim 1, wherein the first image data is obtainedby the reading unit reading a white color surface of a document readingposition instead of a chart in which an image has not been formed by theimage forming unit.
 14. The apparatus according to claim 1, wherein achart in which an image has not been formed by the image forming unit isa blank paper.
 15. The apparatus according to claim 1, wherein thereading unit and the image forming unit are included in an image formingapparatus connected to the apparatus.
 16. A control method of anapparatus comprising: obtaining first image data obtained by reading,performed by a reading unit, a chart on which an image has not beenformed by an image forming unit and second image data, obtained byreading, performed by the reading unit, a chart formed by the imageforming unit; and changing the second image data using the first imagedata and estimating a cause of an abnormality that has occurred in theimage forming unit from a feature amount obtained by analyzing thechanged second image data.
 17. A computer-readable storage mediumstoring computer executable instructions for causing a computer toexecuted a control method of an apparatus, the method comprising:obtaining first image data obtained by reading, performed by a readingunit, a chart on which an image has not been formed by an image formingunit and second image data, obtained by reading, performed by thereading unit, a chart formed by the image forming unit; and changing thesecond image data using the first image data and estimating a cause ofan abnormality that has occurred in the image forming unit from afeature amount obtained by analyzing the changed second image data.